In 3D graphics rendering means the calculation of the final image from the scene that includes models, textures, lights, special effects and cameras. The final image will be a 2D image made of pixels. Utilizing materials, lighting techniques, and renderer's settings one can render multitude of different images from a single 3D scene. Often the goal is to produce realistic rendering, for example in live action movies the goal is to render 3D effects as realistically as possible as it is a cheaper and easier alternative to building sets or hiring extras for a scene.

Photo Realistic Rendering:

Photo Realistic Render of 3D Diamonds

With technology continuing to improve at a rapid rate renders from 3D sofwares are becoming more and more realistic. The ability to apply and map bitmap texture images is a big part of this realism but the key to real photo realism is generally attention to detail when lighting the scene but lighting a scene realistically is also one of the most challenging aspects of producing photo realistic renderings. If you haven't already, please see the article of the basics of 3D lighting types to help you get started.

Clay Model Rendering:

A Clay Render of a 3D Model

When 3D modeler's present their modelling skills they often produce a clay render. Clay render means a rendering which looks like a picture of a clay model. The idea of a clay render is to bring out the form of the model. This is not really a rendered effect however as it is generally the default form of a non textured model or a model without materials. However good lighting is necessary to effectively showcase a model in a clay style render.

Wireframe Rendering:

A wireframe Render of a 3D Model

The purpose of wire rendering is to reveal the polygon structure of the model. Wire rendering displays only edges of the polygons. Wire render and clay render are often combined.

Cell Shading / NPR Rendering:

A Cell Shading Render

Cell Shading is a from of Non-photo realistic rendering (NPR). In contrast to traditional computer graphics, which has focused on photo realism, NPR is inspired by artistic styles such as painting, drawing, technical illustration, and animated cartoons and focuses on enabling a wide variety of expressive styles for digital art. NPR has appeared in movies and video games in the form of "cartoon shading", as well as in architectural illustration and experimental animation.

An example of a modern use of NPR is that of cell-shaded animation as seen above. Another form of NPR is cartoon style rendering means a material / rendering method that produces an image that looks like a hand drawn picture.